You didn't catch my question man. I ask if anyone have this engine and if he use an expansion at the shaft so the prop is fully out of the cawl. I respect your opinions about engines but no thanks. I'm stack with OS engines here i live. They are one of the TOP brands in planes and also in cars since i have 3 of them and they rock. I want the 46 size, and i will go as the manufacturer says. A 70 engine is the biggest i can put, so the OS FL-70. Do you have a UCD?